The HBF4 (0.1 equiv)-catalyzed Mannich-type reactions of ketene silyl acetals with aldimines proceeded smoothly in water in the coexistence of as low as 1 mol% of SDS. Furthermore, the Mannich-type reaction also took place in water in the absence of SDS by means of 0.3 equiv of HBF4 to afford the corresponding β-amino esters in high yields.
HBF4(0.1 equiv)催化的酮烯
硅缩醛与醛
亚胺的曼尼希型反应在
SDS存在下于
水中顺利进行,且
SDS的用量低至1 mol%。此外,即使在
SDS不存在的情况下,通过使用0.3 equiv的 ,曼尼希型反应也能在
水相中发生,高效地生成相应的β-
氨基酯。